Dental engine.



0. H. & A. F. PIEPER.

DENTAL ENGINE.

APPLIUATION FILED MAR. e, 1911.

Patented Oct. 8, 1912.

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DENTAL ENGINE.

APPLIoATIoN FILED MAR. s, 1911.

1,040,577. Patented Oct. 8, 1912.

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OSCAR H. PIEPER AND ALPHONSE F. PIEPER, F ROCHESTER, NEW YORK.

DENTAL ENGINE.

Specification of Letters Patent.

Patented Get. 8,1912.

Application filed March 6, 1911. Serial No. 612,559.

T0 all 'whom t may concern.'

Be it known that we, OSCAR H. Pmrnn and ALPHONSE F. Plurale, both of Rochester', in the county of Monroe and State of New York, have invented certain new and useful Improvements in Dental Engines; and we do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification, and to t-he reference-numerals marked thereon.

The present invention relates to dental engines, and has for an object to provide ian :improved construction in which the motor is arranged so as to act as a counterbalance for the supporting arm, while at the same time its weight is disposed so that it does not interfere with the turning of the supporting arm about a vertical axis.

Another object of the invention is to provide a simple operative connecting means between the arm and the motor, so that the parts will act freely in their counter-balanc ing relation, and the motel' will have a comparatively small range of movenlent.

A further object of the invention is to provide means for maintaining constant tension and taking up the slack in the cable which connects the motor and the hand-piece, as the arm is lowered.

To these and other ends the invention consists in certain improvements and combinations of parts all as will be hereinafter unore fully described, the novel features being pointed out in the claims at the end of the specification.

In the drawings: Figure 1 is a side view in elevation of the engine, showing the supporting arm raised to its uppermost position; Fig. 2 is a side view in elevation, with parts broken away, showing the supportingr arm in lowermost position; Fig. 3 is a view in front elevation, with parts broken away,

showing the arm in lowermost position, and Fig. 4: is a view in top elevation, showing the arm in lowermost position.

In the embodiment of the invention herein illustrated, there is employed an attaching member or bracket 1 having upper and lower arms Q on which turns a frame 3. Re movable bearings l are provided which cooperate with bearing recesses in the bracket and frame, respectively, so that the latter may swing about a vertical axis, and the weight be equally distributed between the upper and lower arms of the bracket. The frame 3 is provided with a pair of parallel arms 5 between which is pivoted the supporting arm or member of the engine on va horizontal axis at G.

The supporting arm comprises, generally, a pivot member provided with a cam surface 8, the radius of the cam, relative to pivot point G, increasing toward its lower end. Connected to the member 7 are tubular rods 9 which are joined at their upper ends by the yoke 1 0. ,llxtending through the yoke 1() is a rod 1l, provided at its outer end with a pendant arm 12 carrying a handpiece connceiling-arm 13 which has at its outer end the handpieee 14. The inner end of the rod 11.1 may arry a member 15, provided with guides lt through which the rods 9 travel, a pulley being suitably provided also at the end of the rod 11, to permit the teleseoping of the supporting arm while maintaining the cable more or less taut.

The motor for driving the handpiece is preferably movable in a vertical direction, and to this end the iframe 3, on which the motor is supported, is of yoke formation, its arms being provided on their opposed faces with guides 17 receiving guide projections 1S, carried by the motor.

In dental engines of this cluiracter, where the motor constitutes a counter-balance for the supporting arm, (mnsiderable diilculty has been experienced in the operation and effectiveness of the cable due to the vertical movement of the motor, aud to obviate this there is provided a frictional connection between the motor and supporting arm, and comprising, in the present embodiment, a member 19, in the form of a bracket, connected to and carried by the motor, and movable between thc arms 5 of the frame 3. The member 19 is provided with an angularly arranged surface 20 which cooperates with the cam surface 8 on the pivot member 7. The member 19 is provided with a guide projection Q1, movable within a guide in the frame 3, and held in position by a stationary bearing-block 22 and yieldable bearing-blocks 2i-l, which are heldin position by means of the spring ei'mtaining screw caps 211. ln this way, a bearingis provided which permits free vertical movement of the member 19 as it is actuated by the cam surface 8 of the supporting arm. Lowering of the supporting arm acts, through the cam surface and member 19, to raise the motor, and so counter-balance the arm. The frictional engagement between surface Q0 and cam 8 permits raising and lowering the arm while ymaintaining a balance at any position, and

results in a certain sliding action or lost motion between the engaging parts, the actual length of operative surface on cam 8 being somewhat shorter than that on the surface 20. Owing to the sliding action between the cams, the angular arrangement of the surface 2O carried by the motor, and the form of the cam 8 having an increasing radius toward its lower end, the supporting arm has a complete movement from horizontal to vertical position while the motor moves a comparatively short distance in its counterbalancing relation, As the arm is lowered, its leverage or lifting effect increases, owing to the fact that the cam 8 is so formed that the point at which it contacts with the surface 20 constantly becomes farther from the pivotal point of the cam, and this causes a perfect counter-balancing of the parts at any point of adjustment of the arm.

The handpiece, of course, may be adjusted to assume any position, this being assisted by the pivoting of the frame 3.

1t has been found that in dental engines of this character, when the supporting arm is lowered, the cable connecting` the motor and handpiece becomes slightly slack, and to overcome this tendency, there is provided in the present invention, means for moving a pulley relatively to the cable, as the supporting arm is lowered. To this end pulleys 25 are provided carried by arms 26 which are pivoted at 27 to the frame 3. The arms Q6, which carry the pulleys have lugs 28 on their lower faces, arranged to contact with cams 29, which are carried by the pivot member 7. The operative surfaces of the cams 29 are so formed that when the supporting arm is raised to its uppermost position, the pulleys are slightly nearer the pivot point 6, and as the supporting arm is lowered, the pulleys are moved away from the pivot point a distance corresponding` to the extent to which the arm is lowered, and when the arm is in its lowermost position the pulleys are at the greatest distance from the pivot point. The cams are curved upwardly slightly at their outer ends, as indicated at 80, to raise the pulleys, just as the arm reaches its uppermost position, sufficiently to retain the cable in the pulley grooves. 1t will be seen from the foregoing that there has been provided a simple mechanism for connecting a motor and a supporting` arm operatively so that the motor moves through the slightest possible distance, and the desired balancing effect is obtained.

Further, the invention affords extremely simple means for maintaining constant the tension of the cable between the motor and handpiece, as the supporting arm is lowered and in proportion to the extent of such lowering, insuring a free, easy movement of the engine under all conditions.

YWe claim as our invention:

1. ln a dental engine, the combination with a frame mounted to turn about a vertical axis, of a supporting arm mounted to turn on the frame about a horizontal axis, a hand piece carried by the supporting arm, a counter-balance comprising a motor, driving connections leading from the motor to the hand piece, means having frictional engagement with said supporting arm and connecting the latter with the counterbalance whereby sliding action is permitted between the supporting arm and the frictional engaging means, and means for guiding the counter-balance vertically on the frame 2. ln a dental engine, the combination with a frame mounted to turn about a vertical axis, of a supporting arm mounted to turn about a horizontal axis, a hand piece carried by the supporting arm, a counterbalance, and means having frictional and sliding engagement with the supporting arm and operatively connecting the lat-ter with the counter-balance.

3. ln a dental engine, the combination with a frame mounted to turn about a vertical axis, of a supporting arm mounted to turn on the frame about a horizontal axis, a hand piece carried by the supporting arm, a counter-balance comprising a motor, driving connections leading from the motor to the hand piece, and means operatively connecting the counter-balance with the supporting arm comprising a lever on one of the parts cooperating frictionally and slidably with the other part and capable of movement independently thereof.

4;.- ln a dental engine, the combination with a frame mounted to turn about a vertical axis, of a supporting arm mounted to turn on the frame about a horizontal axis, a hand piece carried by the supporting arm, a counter-balance, and means operatively connecting the counter-balance with the supporting arm, said means having frictionally engaging surfaces adapted to allow sliding action between the surfaces.

5. 1n a dental engine, the combination with a frame mounted to turn about a vertical axis, of a supporting arm mounted to turn on the frame about a `horizontal axis, a handpiece carried by the supporting arm, a counter-balance, means operatively connecting the counter-balance with the supporting arm consisting of a cam carried by one of the parts having frictional and slidable engagement with a surface on the other part, and means for guiding the counterbalance vertically on the frame.

6. In a dental engine, the combination with a frame mounted to turn about a vertical axis, of a supporting arm mounted to turn on the frame about a horizontal axis, a handpiece carried by the supporting arm, a counter-balance, means operatively connecting the counter-balance with the supporting arm consisting of a curved surface on one of the parts in frictional and slidable engagement with a coperating surface on the other part, and means for guiding the eountenbalance vertically on the frame.

7. In a dental engine, the combination with a frame mounted to turn about a vertical axis, of a supporting arm mounted to turn on the frame about a horizontal axis, a hand piece carried by the supporting arm, a countenbalance, means having frictional and sliding engagement with the supporting arm for operatively connecting the latter with the counter-balance, and means for guiding the counter-balance vertically on the frame.

8. In a dental engine, the combination with a handpiece and a supporting arm therefor mounted to turn about a horizontal axis, a motor for driving the handpiece, a driving cable leading from the motor and connected to the handpiece, and cam actuated means in engagement with the cable and automatically movable relatively thereto to maintain the tension of the cable constant as the arm is lowered.

9. In a dental engine, the combination with a handpiece and a supporting arm therefor mounted to turn about a horizontal axis, a motor for driving the handpiece, a driving cable leading from the motor and connected to the handpiece, a pulley in engagement with the cable, and cam actuated means carried by the supporting arm for automatically moving the pulley relatively to the cable to maintain the tension thereof constant as the arm is lowered.

10. In a dental engine, the combination with a frame mounted to turn about a vertical axis, of a supporting arm mounted to turn about a horizontal axis on the frame, a handpiece on the arm, a motor for driving the handpiece, means operatively connecting the motor and the arm whereby the latter is balanced by the former, a driving cable leading from the motor and connected to the handpieee and means controlled by the supporting arm and automatically movable relatively to the cable to maintain the tension thereof constant as the arm is lowered.

l1. In a dental engine, the combination with a frame mounted to turn about a vertical axis, of a supporting arm mounted to turn about a horizontal axis on the frame, a handpiece on the arm, a motor for driving the handpiece, means operatively connecting the motor and the arm whereby the latter is balanced by the former, a driving cable leading from the motor and connected to the handpiece, a pulley in engagement with the cable, and cam actuated means for automatically moving the pulley relatively to the cable to maintain the tension thereof constant as the arm is lowered.

12. In a dental engine, the combination with a frame mounted to turn about a vertical axis, of a supporting arm mounted to turn about a horizontal axis on the frame, a handpiece on the arm, a motor for driving the handpiece, means operatively connecting the motor and the arm whereby the latter is balanced by the former, driving cable leading from the motor and connected to the handpiece, a pulley in engagement with the cable, and a cam surface carried by the supporting arm and controlling the position of the pulley relatively to the cable to maintain the tension thereof constant as the arm is lowered.

OSCAR II. PIEPER. ALPHONSE F. PIEPER.

Witnesses:

R. L. FITCH, A. F. Mn'roALr.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of latents,

Washington, I). C. 

